程序代码：

PUBL gcOldDir,vcxname

gcOldDir = SET('DEFAULT') + SYS(2003)
SET DEFA TO "&gcOldDir"
******************************************************************************
&&获取程序运行名称
Declare INTEGER GetModuleHandle IN kernel32 INTEGER lpModuleName
vcxid = ALLTRIM(STR(GetModuleHandle(0)))

Declare INTEGER GetModuleFileName IN kernel32;
INTEGER hModule,;
STRING @ lpFilename,;
INTEGER nSize

lpFilename = SPACE(250)
lnLen = GetModuleFileName (0, @lpFilename, Len(lpFilename))
vcxname = JUSTFNAME(ALLTRIM(Left (lpFilename, lnLen)))
******************************************************************************
#DEFINE ERROR_ALREADY_EXISTS 183 
DECLARE INTEGER GetLastError IN WIN32API
DECLARE INTEGER CreateMutex IN WIN32API INTEGER Security,;
SHORT Owned,;
STRING@ MutexName
DECLARE SHORT CloseHandle IN WIN32API INTEGER

PUBLIC hMutex, iResult, bCanRun
hMetux=CreateMutex(0,0,vcxname)
iResult=GetLastError()
DO CASE 
CASE iResult==0
bCanRun=.T.
CASE iResult==ERROR_ALREADY_EXISTS
MessageBox("程序已经运行。"+SPACE(2),64,"提示")
bCanRun=.F.
OTHERWISE 
bCanRun=.F.
MessageBox("GetLastError() returned "+ ltrim(str(iResult))) 
ENDCASE 

IF bCanRun ==.F.
=CloseHandle(hMutex)
QUIT
ENDIF

程序代码：

DECLARE LONG CreateMutex  IN Kernel32 STRING@, LONG, STRING@
DECLARE LONG GetLastError IN Kernel32
DECLARE LONG CloseHandle  IN Kernel32 LONG
szPrg  = PROGRAM()
hMutex = CreateMutex(NULL, 0, @szPrg)
IF GetLastError() != 183    && ERROR_ALREADY_EXISTS
    MESSAGEBOX(szPrg + " 正常启动运行")
ELSE
    MESSAGEBOX(szPrg + " 不能重复运行")
ENDIF
CloseHandle(hMutex)
CLEAR DLLS
RETURN